Porous particles loaded with cosmetically or pharmaceutically active compounds

ABSTRACT

The present invention relates to individualized porous particles, characterized in that they have a volume-average diameter of less than or equal to 10 μm and a specific surface area of greater than or equal to 1 m 2 /g, and in that they comprise at least one cosmetically or pharmaceutically active compound at least present inside said particles.

The present invention relates to individualized porous particles havinga volume-average diameter of less than or equal to 10 μm and containingat least one cosmetically or pharmaceutically active compound, and totheir use in particular for transporting and releasing said activecompound in the pilosebaceous unit.

To increase the efficacy of formulations for topical application,whether they are cosmetic or pharmaceutical in type, a certain number ofmethods have already been proposed which aim to improve the penetrationof the active molecules into the stratum comeum forming the superficiallayer of the skin. By way of examples of these methods, mention will bemade of those using, as vehicle for these active molecules, liposomes,nanocapsules, O/W emulsions, short alcohols, glycols, etc.

The pilosebaceous unit forms, within the stratum corneum, the epidermisand the dermis, an invagination comprising a hair follicle and asebaceous gland. It is the site of considerable biological and enzymaticactivity which has a major effect on the appearance of the skin. Amongthese effects, mention may be made, for example, of the influence of theproduction of the sebum on the greasy or dry nature of the skin, and theinfluence on the growth or on the loss of growth of the body hair or ofthe head hair on the pilosity of the skin. The pilosebaceous unit canalso be the subject of an inflammatory process. Such a process can havevarious causes and can in particular be related to the presence ofmicroorganisms. This process can result in or contribute to themanifestation of a certain number of skin conditions such as acne. Inaddition, the pilosebaceous unit constitutes a potential route ofpassage for agents intended to act on deep skin tissues, for example foragents of the deep antiwrinkle type, of the slimming type, etc.

The structure of this pilosebaceous unit, both by virtue of itsmorphology with the presence of a hair, and by virtue of its physiologywith a continuous flow of sebum, naturally opposes the penetrationand/or the diffusion of active compounds within and into the depths ofthis structure.

However, methods for targeting active compounds into the pilosebaceousunit have already been proposed.

Thus, Application EP 0 375 520 describes the use of microspheres ofnatural or synthetic polymers or of fatty substances with a meltingpoint above 50° C., loaded at least with an active product, and in whichat least 80% by weight of these microspheres are between 3 μm and 10 μmin diameter, for preferentially transporting the active product into thepilosebaceous unit. The microspheres described in that application areeither microspheres consisting of crosslinked materials, or solidmicrospheres loaded by partial solubilization of their constitutivematerials, and which have a specific surface area of less than 1 m²/g.In addition, the processes for preparing microspheres described in thatdocument, which comprise the encapsulation of the active compound eitherby means of solvents having sufficient affinity with respect to thematerial making up the microsphere, or by the“emulsification-evaporation” method, only allow an approximate controlof the homogeneity of the microspheres obtained and therefore result,besides their low capacity to load the active compound(s), in avariation of this capacity and also in a variation of their capacity torelease the active compound(s) in the pilosebaceous unit.

Application WO 02/07674 proposes a method for increasing the penetrationof an active compound into the pilosebaceous unit using a composition inthe form of microspheres or of liposomes having the property of beingintroduced into the follicle and of swelling therein by virtue ofsubsequently being in contact with a swelling agent, so as to generatetherein a passage into the follicle. However, WO 02/07674 does notprovide any concrete example illustrating the method proposed and doesnot therefore make it possible to verify the effectiveness thereof.

U.S. Pat. No. 6,287,549 describes a method of hair removal using acomposition comprising organic microparticles loaded with chromophoreagents, in which at least 80% by weight of the microparticles used arebetween 3 and 10 μm in size, in order to transport the chromophore agentinto the pilosebaceous unit. These microparticles may be of varioustypes and may be loaded with chromophores either as they are formed, orby impregnation of already formed microcapsules. In thesemicroparticles, the compounds transported are not active compounds assuch, since they require the intervention of an outside factor in orderto be able to exercise an effect. In addition, the exercising of thiseffect does not require their release from the microparticles. Moreover,that document, which explicitly provides for an optional step ofapplication of a composition for solubilizing the chromophores so as toallow their release from the microparticles, does not suggest thepossibility of a passive release and even illustrates the existence of apreconceived idea against this.

U.S. Pat. No. 4,690,825 describes vehicles consisting of porousparticles which are between 10 μm and 100 μm in size, for the controlledrelease of active ingredients. These particles are prepared bycopolymerization of monomers based on styrene or on vinyl stearate andon divinylbenzene, or on methyl methacrylate and on ethylene glycoldimethyl methacrylate, in the presence of a porogen which is also theactive ingredient. There is therefore a risk that the product obtainedwill contain residues from the process for preparing it, which is likelyto affect its innocuity.

Application WO 99/53904 describes soft capsules containing an oilysuspension or a silicone/polyethylene glycol emulsion and sphericalporous microparticles prepared in particular according to U.S. Pat. No.4,690,825 mentioned above. More precisely, this application describesporous microparticles having a mean particle diameter by weight of 20μm, loaded either with retinol or with ascorbic acid.

Finally, U.S. Pat. No. 6,387,995 describes a process for producing anadsorbent polymer in the form of agglomerated, i.e. non-individualized,microparticles with a very low mass by volume ranging from 0.02 g/cm³ to0.1 g/cm³, capable of trapping lipophilic compounds. The amount ofcompound trapped in the particles is negligeable compared with that ofthe compound trapped in the space formed by the agglomerated particles.

It has now been discovered that it is possible to transport at least oneactive compound and to release it in the pilosebaceous unit withincreased effectiveness compared to the embodiments discussed above. Themeans found also makes it possible to improve the encapsulation of theactive compound, compared to the solutions proposed to date, while atthe same time exhibiting a particularly satisfactory innocuity.

According to a first aspect, the present invention relates toindividualized porous particles having a volume-average diameter of lessthan or equal to 10 μm and a specific surface area of greater than orequal to 1 m²/g, comprising at least one cosmetically orpharmaceutically active compound at least present inside said particles.

According to a second aspect, the present invention relates to acosmetic or pharmaceutical composition comprising particles as definedabove.

The expression “porous particles” denotes particles having a structurecontaining pores.

This structure may be of matricial type, like a sponge. It may also beof vesicular type, i.e. the particle has an internal cavity delimited bya porous wall.

The porosity associated with the size of the particles is characterizedquantitatively by their specific surface area. The porous particles ofthe invention have a specific surface area, measured according to theBET method, of greater than or equal to 1 m²/g.

The expression “individualized particles” denotes particles which arenot grouped together in the form of an aggregate or of an agglomerate.These particles have in particular a mass by volume of greater than orequal to 0.15 g/cm³, and in particular ranging from 0.2 to 5 g/cm³.

The expression “cosmetically or pharmaceutically active compound” isintended to mean, in the context of the present invention, a compoundwhich, by itself, i.e. not requiring the involvement of an outside agentto activate it, has biological activity. In addition, this activityneeds the compound to be in direct contact with its target.

The particles used according to the present invention derive frompreformed porous particles, i.e. particles formed in the absence of thecompound(s) to be encapsulated.

For the purpose of the present invention, the expression “loadedparticles” will be used hereinafter to denote the particles according tothe invention in such a way as to distinguish them from the particulatematerial from which they derive and which does not contain activecompound.

The loaded particles according to the invention do not thereforesubstantially contain residues related to the process for producing theparticles from which they derive, which of course constitutes animprovement in terms of innocuity compared to particles which, in orderto load the active compound, must be formed in its presence. Moreover,they are not solid.

The particles of the invention are in particular characterized by a highspecific surface area, measured by BET.

The BET (BRUNAUER-EMMET-TELLER) method is a method well known to thoseskilled in the art. It is in particular described in “The journal of theAmerican Chemical Society”, vol. 60, page 309, February 1938, andcorresponds to the international standard ISO 5794/1 (annexe D). Thespecific surface area measured according to the BET method correspondsto the total specific surface area, i.e. it includes the surface areaformed by the pores.

According to a particular embodiment, the particles of the inventionhave a specific surface area, measured by BET, ranging especially from2.5 to 1000 m²/g, in particular from 3 to 750 m²/g.

As mentioned above, the particles according to the present inventionhave a volume-average diameter of greater than or equal to 10 μm.

In fact, such particles can penetrate into the sebaceous follicle byapplication of a mechanical force. This mechanical force generally comesfrom a massage which, besides the pushing that it exerts, generates apump effect in the follicle.

The particles thus gradually reach the follicle canal in which theactive compound that they are carrying can then diffuse and, possibly,reach the tissues surrounding the follicle canal. On the other hand, thecarrier, which constitutes the particle, is then discarded by virtue ofthe flow of sebum and/or the growth of the body hair, thus making itpossible to avoid any adverse reaction by the organism with respect tothe solid compound constituting the particles.

It should be noted that particles having a diameter of greater than 10μm, even with application of a similar mechanical force, mostly remainlocated on the surface of the skin without penetrating therein, and cantherefore release the active compound only on the cornified layer.

According to a particular embodiment of the invention, the particleshave a volume-average diameter of greater than or equal to 0.1 μm, andin particular ranging from 0.5 to 8 μm.

According to a variant of the invention, the particles are characterizedby virtue of their particle size homogeneity. In particular, they have apolydispersity index, PI, ranging from 1 to 4, and in particular lessthan or equal to 3. This polydispersity index is defined as the ratioD(4.3)/D(3.2), in which D(4.3) denotes the volume-average diameter andD(3.2) denotes the surface-average diameter. These two values arecommonly measured using laser diffraction particle size measuringdevices such as that sold under the name “Mastersizer 2000” by thecompany MALVERN.

The porous particles of the invention may have varied shapes, especiallyglobular, and in particular substantially spherical.

The porous particles from which the loaded particles according to theinvention derive generally consist of materials which are completelyinsensitive, especially in terms of solubilization and plasticization,to the process for encapsulating the active compounds, in particularwhen this involves an organic solvent for the impregnation.

These particles may be of organic, inorganic or mixed type and are mostcommonly provided in the form of a powder with, in particular, a lowvolatility.

As porous particles of organic type, mention will be made, by way ofexample, of particles of Nylon 6, Nylon 6-6, Nylon 12 or Nylon 6-12,such as those sold by the company ATOFINA under the generic name“Orgasol”, and particles of poly(methyl methacrylate) (PMMA) such asthose sold under the name “Covabead®” by the company WAKER.

In a particular embodiment of the invention, the particles used arechosen from the nylon particles mentioned above.

As porous particles of inorganic type, mention will be made, by way ofexample, of particles consisting of silica such as those sold under thename “God Balls” by the company SUZUKI OIL AND FAT or those sold underthe name “Sunsphere H series” by the company ASAHI GLASS, alumina-silicaparticles such as those sold under the name “Zeeosphere®” by the company3M, hydroxyapatite particles such as those sold under the name “ASP®” bythe company SEKISUI PLASTICS, or under the name “Hydroxyzomes” by thecompany ASAHI GLASS, titanium dioxide particles such as those sold bythe company ISHIHARA, and particles made up of a mixture of theseminerals.

In one embodiment of the invention, the particles used are in particularchosen from silica particles and hydroxyapatite particles.

The porous particles used in the present invention may also consist oforganic and inorganic composite materials.

The loaded particles according to the present invention comprise atleast one cosmetically or pharmaceutically active compound, saidcompound being at least present inside the said porous particles. Theactive compound can also be present at the surface of the loadedparticles, but in such a case, it is generally present mostly insidesaid particles.

The ratio by weight of the active compound(s) to the porous particlesnot loaded with active compound(s) is generally from 1/1000 to 10/1, inparticular from 1/100 to 1/1.

The active compounds may be hydrophilic or lipophilic. According to aparticular variant of the invention, the loaded particles comprise atleast one lipophilic active compound. They can also comprise at leastone hydrophilic active compound, it being possible for the latter to besufficiently solubilized by amphiphilic compounds present in the sebumto allow its release.

The active compounds considered hereinafter are, without distinction,hydrophilic or lipophilic.

Among the active compounds, mention may in particular be made of:

-   -   antibacterial agents such as triclosan, IPBC        (iodo-3-propynyl-2-butyl carbamate), benzalkonium chloride,        chlorhexidine, etc.,    -   antifungal agents such as piroctone olamine, zinc pyrithione,        climbazole, rilopirox, ketoconazole, itraconazole, etc.,    -   sebum regulators such as the iminodibenzyl or fluorene        derivatives as described in U.S. Pat. No. 6,355,687, the        substituted secondary amine derivatives as described in U.S.        Pat. No. 6,355,686, the glucuronic acid and glucosamine        derivatives, and their salts, as described in Patent Application        EP 1 219 296, or the combinations of niacinamides with a C₁₁-C₃₀        alkyl or alkenyl ester of salicylic acid as described in Patent        Application WO 02/067889,    -   sebum stimulators such as DHEA and its synthetic or natural        derivatives, α-hydroxylated derivatives of vitamin D1 such as        those described in U.S. Pat. No. 6,369,099,    -   keratolytic agents such as salicylic acid and its derivatives,        for instance more particularly 5-n-octanoylsalicylic acid,        alpha-hydroxy acids such as those, for example, of glycolic        acid, lactic acid or malic acid, and resorcinol,    -   agents for treating acne, such as retinol and its derivatives,        retinoic acid and its all-trans or 13-cis isomers, benzoyl        peroxide, the cytochrome P450 inhibitors as described in U.S.        Pat. No. 6,399,774 and their derivatives, and azelaic acid,    -   antibiotics which may or may not have a macrolide structure, the        avermectin compounds as described in U.S. Pat. No. 6,399,652,        [(2,4,6-triisopropylphenyl)-acetyl]sulphamic acid        2,6-diisopropylphenyl ester or a salt thereof, as inhibitor of        cholesteryl and wax ester synthesis, as described in Patent        Application WO 01/56556,    -   hair loss inhibitors and also hair growth stimulators such as        minoxidil, biotin, finasteride, 2,4 dipyrimidine N-oxide,        panthenol and their derivatives, flavanone T, or more generally        any plant extract, having anti-5-alpha-reductase type I or II        activity,    -   agents which inhibit the growth of head hair or of body hair,        such as the serine proteases described in U.S. Pat. No.        6,407,056, cafeic acid, quercetin, propyl gallate,        nordihydroguaiaretic acid or NDGA, indomethacin, eflornithine        hydrochloride, the plant extracts as described in U.S. Pat. No.        6,171,595, such as the extracts of clove, of rosehip, of burnet,        of gambir, etc., the compounds described in U.S. Pat. No.        6,075,052, tetramisole, sodium orthovanadate, levamisole,        disodium chromoglycate, vanadium nitrate and gallium nitrate as        described in U.S. Pat. No. 6,020,006, and also the compounds        described in Patents U.S. Pat. Nos. 4,885,289, 4,720,489,        5,132,293, 5,096,911, 5,095,007, 5,143,925, 5,328,686,        5,440,090, 5,364,885, 5,411,991, 5,648,394, 5,468,476,        5,475,763, 5,455,608, 5,674,477, 5,728,736 and 5,652,273 and in        Patent Applications WO 94/27586, WO 94/27563 and WO 98/03149.        Use may also be made of the extracts of juniper as described in        U.S. Pat. No. 6,375,948,    -   anti-dandruff agents such as zinc pyrithione,    -   antioxidants such as butylhydroxytoluene (BHT), carotenoids such        as β-carotene, lycopene, canthaxanthine, ubiquinone,        dibutylpentaerythrityl tetrahydroxycinnamate, vitamin E, trolox,        vitamin C and its derivatives,    -   astringents and pore-reducing agents, such as those described in        Patent Application WO 02/32392,    -   antiperspirant agents such as aluminium salts and zirconium        salts,    -   vitamins, other than those mentioned above, and such as vitamin        B3, vitamin K, vitamin H, vitamin PP, vitamin D, vitamin B6 and        their derivatives, and    -   anti-inflammatory agents such as α-bisabolol, dipotassium        glycyrrhizinate, glycyrrhetinic acid and its derivatives,        ellagic acid, ursolic acid, ibuprofen, naproxen, fenoprofen,        carprofen, ketoprofen, steroidal anti-inflammatory agents such        as cortisone, pregnenolone, desonide, and mixtures of        alkolamines and of tyrosine, such as those described in Patent        Application EP 1 192 939.

The loaded particles of the present invention are prepared according toconventional methods, in particular by impregnation.

In particular, the loaded particles according to the invention areobtained by impregnation of preformed porous particles with at least oneactive compound. Advantageously, this protocol does not require thepresence of a porogen.

By way of example, the impregnation process consists in presolubilizingthe compound(s) to be encapsulated in a solvent which is suitable and inan amount necessary and sufficient to impregnate the particles, and thenin bringing this mixture into contact with porous particles inaccordance with the invention. The solvent is then evaporated off untila dry powder is obtained. The powder thus obtained generally containsonly a very small proportion of residual solvent, of the order of 1/10ppm.

As solvents which may be used in such an impregnation process, mentionmay in particular be made of acetone, ethanol, isopropanol,dichloromethane, ethyl acetate, etc. Of course, the choice of solvent ismade taking into account the nature of the components of the porousparticles and of the compounds to be encapsulated.

When the compound to be encapsulated is in the form of a liquid, it maybe brought directly into contact with the porous particles without theaddition of a secondary solvent.

Those skilled in the art will take care to choose the impregnationconditions so as to obtain a dry powder.

The loaded particles of the invention allow specific administration ofsaid cosmetically or pharmaceutically active compound(s) into thepilosebaceous unit.

These particles can be introduced in various cosmetic or pharmaceuticalformulations intended for topical application.

The present invention therefore also relates to a cosmetic orpharmaceutical composition comprising loaded particles as defined above.

Of course, said composition may comprise only one type of particles asdefined above, or else a mixture of such particles.

Generally, the composition contains from 0.1 to 50% by weight, and inparticular from 0.2 to 20% by weight, of particles as defined aboverelative to the total weight of the composition.

The composition according to the invention may also comprise:

-   -   at least one cosmetically or pharmaceutically active compound        intended to act essentially outside the pilosebaceous unit,        and/or    -   at least one cosmetically or pharmaceutically acceptable        additive, and/or    -   a galenic carrier, which may be of any suitable type.

The term “carrier” is intended to denote any mode of vehicle compatiblewith cosmetic or pharmaceutical use, namely of liquid type such aswater, an aqueous-alcoholic solvent, oil, or a mixture thereof, or ofsolid type such as wax for example.

Care will, however, be taken to ensure that the optional additionalcosmetically or pharmaceutically active compound, the optional additiveand the optional carrier do not cause the release of the active compoundin the composition.

According to a particular embodiment, the compositions of the inventionare substantially free of surfactants.

The cosmetic or pharmaceutical composition may be provided in the formof lotions, O/W or W/O emulsions, or aqueous or aqueous-alcoholic gels,or alternatively in anhydrous form, such as sticks, sprays or compact orfree powders.

The compositions of the invention may be care compositions, hygienecompositions or makeup compositions.

They may also be intended, for example, for use on the hair and may inparticular be shampoos, conditioners, hair lotions, in particular forhair care.

They may also be makeup sticks such as lipsticks, or personal hygienesticks such as deodorants.

Examples presented hereinafter are given by way of illustration and arenot limiting in nature.

FIGURE

FIG. 1: Electron micrograph consisting of silica particles containingtriclosan in accordance with the invention.

EXAMPLE 1

Two compositions containing a lipophilic active compound,5-n-octanoylsalicylic acid, namely respectively a gel containing 4 μmporous particles of nylon (“Orgasol®”), which is the subject of theinvention, and an O/W emulsion with the same mean particle size arecompared in terms of pilosebaceous unit-targeting effectiveness. Theamount of active principle, 5-n-octanoylsalicylic acid, is identical inthe two types of composition, and is set at 0.3% by weight.

The Compounds Tested

Composition 1 (according to the invention) Poly(ammoniumacryloyldimethyltaurate) 0.50 g Porous particles of Nylon-12* 4.70 g5-n-octanoylsalicylic acid 0.30 g Poloxamer 338 0.25 g Demineralizedwater 94.25 g *The porous particles of Nylon-12 are sold under the name “Orgasol 2002UD Nat cos” by the company ATOFINA.

Composition 2 (comparative O/W emulsion) Xanthan gum 0.10 g Glycerylstearate 1.00 g Sodium hydroxide 0.10 g Cetyl alcohol 2.00 gOctyldodecanol 9.00 g Glycerol 3.00 g Hydrogenated polyisobutene 2.00 gWater 71.95 g  5-n-Octanoylsalicylic acid 0.30 g Paraffin oil 5.00 gCarbomer 0.30 g PEG-100 stearate 1.00 g Polysorbate 60 4.00 gMethylparaben 0.25 g

The study was carried out on eight volunteer individuals who have oilyskin exhibiting dilated pores on the forehead.

For each individual, after having carefully cleaned the face with soap,4 mg/cm² of the composition to be tested are applied to the left orright side half of the forehead, and the area treated is then massagedfor 1 minute and left to dry for 15 minutes. This application isrepeated for 4 days under the same conditions (i.e. a total treatmentperiod of 5 days with a single daily application).

On day 6, an epidermal sample is taken from each individual bycyanoacrylate strip, applying onto the forehead of each individual aglass slide onto which a drop of cyanoacrylate has been deposited, andthen, after drying, removing said slide, which thus entrains anepidermal sample.

The follicles and the comedones are then removed from said samples andtheir content is extracted in methanol. The amount of active compound isquantified by HPLC.

The results are presented in Table 1 below. TABLE 15-n-Octanoylsalicylic acid Number of comedones in pg per comedone AreaArea Area Area Testers composition 2 composition 1 composition 2composition 1 Enrichment 1 29 34 439 656 50% 2 20 16 282 566 101% 3 2527 121 200 66% 4 30 33 709 1288 82% 5 24 13 571 986 73% 6 29 19 468 83679% 7 11 13 57 259 353% 8 28 25 144 433 201%

It is noted, according to the results set out above, that composition 1according to the invention, which contains the porous particles loadedwith 5-n-octanoylsalicylic acid, makes it possible to significantlyincrease the amount of 5-n-octanoylsalicylic acid in the follicle by arate of at least 50%, compared with a composition in the form of anemulsion containing the same amount of 5-n-octanoylsalicylic acid.

This trial shows the effectiveness of the porous particles of theinvention for transporting active molecules into the pilosebaceous unit.

EXAMPLE 2 Preparation of the Organic Particles Containing an ActiveCompound

Particle composition Porous particles of Nylon-12, sold under the name“Orgasol 2002 7.5 g UD Nat Cos” ® by the company ATOFINA Triclosan 2.5 g

2.5 g of triclosan are solubilized in 50 ml of acetone. 7.5 g of“Orgasol®” are introduced into this mixture. The dispersion is thenintroduced into a rotary evaporator in order to eliminate the acetone. Apowder loaded with triclosan is then obtained.

The powder thus obtained can then be redispersed in water, in a gel orin an emulsion. Care will be taken to ensure that the composition intowhich the particles containing the triclosan are introduced does notpromote leaking of said triclosan into the galenic carrier.

EXAMPLE 3 Preparation of Organic Particles Containing an Active Compound

Particle composition Porous particles of silica sold under the name “GodBalls2 7.5 g EC ®” by the company SUZUKI OILS & FATS Vitamin E 1.5 g5-n-Octanoylsalicylic acid 1.0 g

1.5 g of vitamin E and 1 g of 5-n-octanoylsalicylic acid are solubilizedin 50 ml of acetone. 7.5 g of “God Balls 2 EC®” porous particles areintroduced into this mixture. The dispersion is then introduced into arotary evaporator in order to eliminate the acetone. A powder loadedwith vitamin E and with 5-n-octanoylsalicylic acid is then obtained.

The powder thus obtained can then be redispersed in water, in a gel orin an emulsion. Care will, however, be taken to ensure that thecomposition into which the particles containing the vitamin E and the5-n-octanoylsalicylic acid are introduced does not promote leaking ofthese active agents into the galenic carrier.

Similarly, a powder of particles was prepared with 7.5 g of “God Balls 2EC®” porous particles and 2.5 g of triclosan. The powder is observedunder an electron microscope. A micrograph thereof is shown in FIG. 1.

It is noted that the powder thus obtained consists of individualizedparticles.

EXAMPLE 4 Anti-Acne Cream (Oil/Water Emulsion)

Poly(ammonium acryloyldimethyltaurate) 0.40 g Xanthan gum 0.20 gPreserving agents 0.80 g Disodium EDTA 0.05 g Glycerol 5.00 gDemineralized water 75.04 g  Porous particles according to Example 23.00 g Mixture of cetearyl alcohol/dimyristyl tartrate/C12-15 Pareth-1.50 g 7/PPG-25-Laureth-25 Stearyl alcohol 1.00 g Mixture of glycerylstearate/PEG-100 stearate 2.00 g Cyclohexasiloxane 10.00 g  Ethylhexylmethoxycinnamate 1.00 g Fragrance 0.01 g

This smooth and fresh cream makes it possible to combat problems of acnewith good effectiveness.

EXAMPLE 5 Tonic Lotion

Butylene glycol 1.00 g Zinc oxide 0.50 g Lactic acid 0.10 g Glycerol1.00 g Propylene glycol 0.20 g PEG-60 hydrogenated castor oil 0.15 gEthanol 5.00 g 30 nm colloidal silica 0.50 g Porous particles accordingto Example 2 1.00 g Demineralized water 90.33 g  Extract of Hamamelisvirginiana 0.0002 g  Menthoxypropanediol 0.01 g Methylparaben 0.20 gFragrance 0.01 g

EXAMPLE 6 W/O Emulsion

Phase A: Isohexadecane 8.00 g Squalane 3.70 g Polydimethylsiloxane(viscosity: 10 cst) 4.10 g Apricot kernel oils 2.30 g Lubrizol 5603 1.90g Phase B: Ascorbic acid 2.00 g 50% potassium hydroxide 1.20 gDemineralized water 67.80 g  Glycerol 5.00 g Preserving agents 1.00 gPhase C: Particles according to Example 2 3.00 g

Phase B is emulsified slowly, at ambient temperature, in phase A, andthen phase C is added.

1. Individualized porous particles, characterized in that they have avolume-average diameter of less than or equal to 10 μm and a specificsurface area of greater than or equal to 1 m²/g, and in that theycomprise at least one cosmetically or pharmaceutically active compoundat least present inside said particles.
 2. Particles according to claim1, characterized in that they have a specific surface area ranging from2.5 to 1000 m²/g, and in particular from 3 to 750 m²/g.
 3. Particlesaccording to either one of the preceding claims, characterized in thatthey have a mass by volume of greater than or equal to 0.15 g/cm³, andin particular ranging from 0.2 to 5 g/cm³.
 4. Particles according to anyone of the preceding claims, characterized in that they have avolume-average diameter of greater than or equal to 0.1 μm, and inparticular ranging from 0.5 to 8 μm.
 5. Particles according to any oneof the preceding claims, characterized in that they have apolydispersity index ranging from 1 to 4, and in particular less than orequal to
 3. 6. Particles according to any one of the preceding claims,characterized in that they are provided in the form of a powder. 7.Particles according to any one of the preceding claims, characterized inthat they derive from organic porous particles.
 8. Particles accordingto claim 7, characterized in that said organic porous particles arechosen from particles of Nylon 6, Nylon 6-6, Nylon 12 and Nylon 6-12 andparticles of poly(methyl methacrylate).
 9. Particles according to anyone of claims 1 to 6, characterized in that they derive from inorganicporous particles.
 10. Particles according to claim 9, characterized inthat said inorganic porous particles are chosen from particles ofsilica, of alumina-silica, of hydroxyapatite, of titanium dioxide or ofmixtures thereof.
 11. Particles according to any one of the precedingclaims, characterized in that they derive from porous particles made ofan organic and inorganic composite material.
 12. Particles according toany one of the preceding claims, characterized in that the ratio byweight of the active compound(s) to the porous particles not loaded withactive compound(s) is from 1/1000 to 10/1, and in particular from 1/100to 1/1.
 13. Particles according to any one of the preceding claims,characterized in that they comprise at least one cosmetically orpharmaceutically active compound chosen from antibacterial agents,antifungal agents, sebum regulators, sebum stimulators, keratolyticagents, agents for treating acne, antibiotics, hair loss inhibitors/hairgrowth stimulators, agents which inhibit the growth of head hair or ofbody hair, anti-dandruff agents, antioxidants, astringents,pore-reducing agents, antiperspirant agents, vitamins, anti-inflammatoryagents, and mixtures thereof.
 14. Cosmetic or pharmaceuticalcomposition, characterized in that it comprises particles as defined inany one of claims 1 to
 13. 15. Cosmetic or pharmaceutical compositionaccording to claim 14, characterized in that the proportion by weight ofsaid particles relative to the total weight of said composition is from0.1 to 50%, and in particular from 0.2 to 20%.
 16. Cosmetic orpharmaceutical composition according to either one of claims 14 and 15,characterized in that it is provided in the form of a lotion, an O/Wemulsion, a W/O emulsion, or an aqueous or aqueous-alcoholic gel, or inanhydrous form, such as a stick, a spray or a compact or free powder.